Six by-elections on 7 December, and Brantford is the one that could change hands
Mark Carney has called six federal by-elections for the same day. Five look safe for the party that held them. In Brantford–Brant South, a Conservative seat, our projection has the Liberals narrowly ahead.
Polling Forecast
3 min read
data as of 11 November Written in house from our poll data and our forecast.
On Sunday 1 November Mark Carney called by-elections in six vacant ridings for Monday 7 December: three in Quebec, two in Ontario and one in Saskatchewan. Advance polls run from 27 to 30 November (CP24).
By-elections are not general elections. Turnout is low, local candidates matter more, and governments usually do worse in them than in the national polls. But this government has done well in them. The Liberals won three in April, in Terrebonne, University–Rosedale and Scarborough Southwest, and on 31 August they took Chicoutimi–Le Fjord from the Conservatives and held Beaches–East York and North Vancouver–Capilano. Thirteen of the 343 MPs elected in 2025 have since left the House.
Here are the six, with who held each and what our general-election projection says about it today.
Brantford–Brant South (Ontario): the one to watch
Held by the Conservatives. Larry Brock won it in 2025 with 52.4% to the Liberals' 41.1% and resigned in September to go back to the Crown attorney's office. Our projection has the Liberals ahead by 0.6 points, a 52% chance of a Liberal gain: Ontario has moved towards the Liberals since April 2025, and a seat with an 11-point Conservative margin is now on a knife edge.
The Conservative campaign has started badly. The party appointed Brantford's mayor, Kevin Davis, as its candidate without a local nomination contest, and Dave Carrol, a pastor and longtime Conservative who wanted the nomination, is running as an independent. "Party leadership chose to appoint another candidate, skipping the process we have valued for decades," he said. Any vote he takes comes mostly from the Conservatives.
Scarborough North (Ontario)
Held by the Liberals. Shaun Chen won 63% here in 2025 and resigned in August because of the effects of a car crash; he has since won a seat on Toronto city council. The Liberals are running James Li, an accountant. Our projection: Liberal by 44 points.
Laurier–Sainte-Marie (Quebec)
Held by the Liberals. Steven Guilbeault, the former environment minister, left after a public disagreement with Carney over climate policy. The Liberals have recruited Guy Cormier, the former head of Desjardins; the Bloc is running Zumretay Arkin, a former vice-president of the World Uyghur Congress; the NDP, Nima Machouf, who came second in 2025. Our projection: Liberal by 28 points.
Rosemont–La Petite-Patrie (Quebec)
Held by the NDP. Alexandre Boulerice resigned in August to run for Québec solidaire, and won. It was the only riding the NDP held east of Manitoba. The NDP is running the activist Pierre Céré; the Liberals, Jean-Sébastien Vallée, who came second in 2025. Our projection: NDP by 15 points, a 92% chance of a hold. Losing it would leave the NDP with no seat in Quebec.
Saint-Hyacinthe–Bagot–Acton (Quebec)
Held by the Bloc. Simon-Pierre Savard-Tremblay left the Bloc caucus in June to run for the Parti Québécois, and won. The Liberals are running Chantal Soucy, a former CAQ member of the National Assembly for eight years; the Bloc, Caroline Emond, a former director general of the International Dairy Federation. Our projection: Bloc by 16 points, a 92% chance of a hold.
Yorkton–Melville (Saskatchewan)
Held by the Conservatives. Cathay Wagantall won 77.5% in 2025. The Liberals have never won the riding since it was created in 1968, but they have recruited Yorkton's mayor, Aaron Kienle; the Conservative candidate is the farmer Nelson Pohl. Our projection: Conservative by 47 points.
What a good night looks like
For the Liberals, a good night is Brantford. Five holds and a gain would add to Carney's majority and extend his run of by-election wins since April. For the Conservatives, holding Brantford despite the row over the candidate would be the first sign in months that their slide in Ontario has stopped. Nanos, which tracks the race weekly, had the Liberals at 45.4% and the Conservatives at 28.9% at the end of October (Nanos).
For the NDP and the Bloc, the night is about survival in Montreal and the Montérégie. Our projections, riding by riding, are on the by-elections page.
Polling Forecast reads every poll in ten countries, corrects for how pollsters have missed before, and turns them into seats. Our forecasts, the polls and our methods are free to explore.
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